| abstract |
N/A. Proteins similar to alpha2-macroglobulin (alpha (2)-M). This group also contains the pregnancy zone protein (PZP). Alpha(2)-M and PZP are broadly specific proteinase inhibitors. Alpha (2)-M is a major carrier protein in serum. The structural thioester of alpha (2)-M, is involved in the immobilization and entrapment of proteases. PZP is a trace protein in the plasma of non-pregnant females and males which is elevated in pregnancy. Alpha (2)-M and PZ bind to placental protein-14 and may modulate its activity in T-cell growth and cytokine production contributing to fetal survival. It has been suggested that thioester bond cleavage promotes the binding of PZ and alpha (2)-M to the CD91 receptor clearing them from circulation. |